Human H5 avian flu cases grow in Calif. and emerge in Ore.

AGDAILY Bites

• Oregon’s first case has been documented, but no evidence of person-to-person transmission.

• California has seen five new cases.

• Nationally, there have been 508 HPAI outbreaks across 15 states this year.

AGDAILY Discussion

The Oregon Health Authority has reported the state’s first human case of highly pathogenic avian influenza H5, while California’s Department of Public Health announced five new infections among farm workers, bringing the state’s total to 26 since early October. Nationally, the Centers for Disease Control and Prevention has confirmed 52 human cases of H5 avian flu so far this year.

The Oregon case, announced on their website on Friday, is linked to an outbreak at a Clackamas County poultry operation that was confirmed on October 24. This outbreak affected a facility with 150,000 birds. The individual experienced mild symptoms, received antiviral treatment with oseltamivir, and has fully recovered. Household members were also treated prophylactically. Health officials have withheld details about the patient and the specific location to protect privacy.

Clackamas County Public Health Officer Dr. Sarah Present emphasized that the case was identified through close monitoring of individuals exposed to the outbreak.

“There is no evidence of person-to-person transmission, and the risk to the public remains low,” she stated.

“Clackamas County Public Health Division has been closely monitoring people exposed to the animal outbreak, which is how this case was identified. The individual experienced only mild illness and has fully recovered,” she added.

California’s five new cases include two in Madera County, one in Fresno County, and others from unidentified locations. The cases in Madera and Fresno counties were associated with exposure to infected dairy cattle, marking a shift from earlier outbreaks concentrated in poultry farms. The infected individuals have mild symptoms, are receiving antiviral treatment, and are isolating at home. Officials reported no evidence of person-to-person transmission in these cases.

Madera County officials highlighted that their cases, one confirmed and one presumptive positive, are unrelated, indicating separate incidents of animal-to-human transmission.

National and animal outbreak updates

The CDC and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service have confirmed a growing number of animal outbreaks. California alone has reported 291 outbreaks in dairy cattle and additional outbreaks in poultry operations, including broiler and turkey farms in Fresno and Merced counties. These developments contribute to the national total of 508 HPAI outbreaks across 15 states this year.

Public health and agricultural officials continue to emphasize the importance of protective measures, including personal protective equipment for farmworkers, symptom education, and close monitoring of exposed individuals. These efforts aim to mitigate risks and contain the spread of the virus.

As the situation evolves, the CDC advises the public to avoid direct contact with infected animals and contaminated materials and to ensure all dairy and poultry products are pasteurized or cooked thoroughly before consumption.